This invention relates to dental cements. More specifically, this invention relates to dental resin cements having surprising handling characteristics.
Resin cements are utilized primarily for aesthetic bonding of aesthetic indirect appliances such as veneers, inlays, onlays, crowns and bridges. Resin cements generally provide excellent physical properties such as high compressive and tensile strength and low wear resistance, and are often used for bonding in difficult indirect bonding situations such as non-parallel or short crown preps.
Handling characteristics of currently commercially available resin luting cements for indirect appliances can cause difficulty in seating for indirect appliances due to resistance, clean-up difficulties due to low viscosity or shear dependence, fast or slow setting characteristics or stringiness.
Dental resin cement materials having unique handling properties are provided that comprise a) filler, b) polymerizable resin, and c) a polymeric handling modifier that is dispersed in the polymerizable resin at 25xc2x0 C. and that has a molecular weight of between about 500 and 100,000. Components a) b) and c) are present in an amount effective to achieve a Viscosity vs Shear Rate Curve that fits a power law model of F(x)=A xB. The correlation value of the material to this curve is greater than 0.85 for both the increasing and decreasing shear rate curves, and the value of B is less than about xe2x88x920.01.
Resin cements are also provided that comprise acid functionality and water, but which do not comprise an acid reactive filler. Such cements may be self etching, thereby avoiding the need to carry out a separate acid etch step.